1. Technical Field
The present invention relates to an electric connection box which is mounted on a vehicle and to which a metal terminal of a wire installed on the vehicle is connected.
2. Background Art
An electric connection box which is the generic name for a fuse block, a relay box and a junction block and receives therein various electrical parts such as fuses, relays, bus bars is mounted on a vehicle. As shown in FIG. 8, such an electric connection box 500 includes a box body 501, a metal terminal 503, etc. The box body 501 includes a body portion 505, a plurality of cassette blocks 507, an upper cover (not shown), and a lower cover 509. The body portion 505 is made of an insulative synthetic resin, and is molded by a well-known injection molding method. The cassette blocks 507 are formed into a box-like shape, and are so sized as to be received within the body portion 505.
Electrical parts such as relays 511, fuses 513 and so on are mounted on upper surfaces 507a of the cassette blocks 507. Further, a terminal mounting portion 515 is provided at the surface of one of the cassette blocks 507. A pair of opposed lock projections 517, 517 are formed on the body portion 505, and a rotation prevention projection 519 is provided between the lock projections 517 and 517. When the cassette block 507 having the terminal mounting portion 515 is incorporated into the body portion 505, the rotation prevention projection 519 shown in FIG. 9 is disposed between the lock projections 517 and 517.
As shown in FIG. 10, the metal terminal 503 is formed into a one-piece, and includes a flat electrical contact portion 521, a reinforcing bridge portion 523, a wire connection portion 525, and an upstanding piece portion 527. The electrical contact portion 521 of the metal terminal 503 is superposed on a metal plate member 529 of the terminal mounting portion 515, and a bolt 531 is passed through a notch 533 formed in the electrical contact portion 521, and is threaded into a nut (not shown) disposed under the metal plate member 529. By doing so, the metal terminal 503 is mounted on the terminal mounting portion 515, with the electrical contact portion 521 held between the metal plate member 529 and a head 531a of the bolt 531.
The electrical contact portion 521 is slid in a direction K along a longitudinal direction of the notch 533, and a threaded portion of the bolt 531 provided at the terminal mounting portion 515 is passed through the notch 533, and the electrical contact portion 521 is pushed into the terminal mounting portion 515 until the threaded portion is brought into abutting engagement with an inner end 533a of the notch 533. By doing so, the electrical contact portion 521 is inserted between the metal plate member 529 of the terminal mounting portion 515 and the head 531a of the bolt 531. At this time, upstanding portions 535 and 535 of the metal terminal 503 slide respectively over the lock projections 517 and 517, and are retained respectively by the lock projections 517 and 517 from opposite sides, and also the rotation prevention projection 519 is fitted into the notch 533 through an entry port formed by the upstanding portions 535 and 535 and an interconnecting portion 537, so that the metal terminal 503 is provisionally fixed. Then, the bolt 531 is tightened, so that the electrical contact portion 521 is held between the head 531a of the bolt 531 and the metal plate member 529, thereby fixing the metal terminal 503 to the terminal mounting portion 515. By doing so, the rotation of the metal terminal 503 due to the rotation of the bolt 531 during the bolt-tightening operation can be effectively prevented (see JP-A-2007-282399).
In the above usual electric connection box 500, when inserting the metal terminal 503 into the terminal mounting portion 515, the upstanding portions 535 and 535 are pressed respectively against the pair of lock projections 517 and 517 formed at the body portion 505, and are slid respectively over the lock projections 517 and 517, and then are retained respectively at the rear sides of the lock projections 517 and 517, and by doing so, the rotation of the metal terminal 503 due to the rotation of the bolt during the bolt-tightening operation is prevented. Therefore, at the time when the metal terminal 503 is slid to be inserted into the terminal mounting portion 515, an inserting force for elastically deforming the lock projections 517 and 517 is required, and the operation often lowers the efficiency. Furthermore, with the lock structure utilizing the elastic force, it is difficult to obtain a high retaining force, and the retained condition of the metal terminal is liable to be canceled, and also wear and fatigue occurred when the operation is repeated, and this leads to a fear that the retaining force might be lowered.